Artifact-less coded aperture imaging in the x-ray band with multiple different random patterns
Artifact-less coded aperture imaging in the x-ray band with multiple different random patterns
复制标题
X 射线波段内具有多种不同随机图案的无伪影编码孔径成像
DOI：
10.1117/1.jatis.6.3.035002
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Tamagawa Toru
中科院分区：
文献类型：
--
作者：
Kasuga Tomoaki;Odaka Hirokazu;Hatauchi Kosuke;Takashima Satoshi;Tamba Tsubasa;Aizawa Yuki;Hashiba Soichiro;Bamba Aya;Zhou Yuanhui;Tamagawa Toru
编码孔径成像技术是天体物理观测中一种有用的X射线成像方法。然而，在解码图像中存在成像噪声或所谓的伪影是该方法的缺点。我们提出了一种编码孔径成像方法，使用多个不同的随机模式，显着减少图像伪影。该孔眼掩模包含多个不同的图案，每个图案在其解码图像中生成不同的伪影分布。通过对不同模式的所有解码图像求和，消除了伪影分布，并且我们获得了非常准确的图像。我们证明了这一概念的成像实验的单色16 keV硬X射线束在同步加速器光子设施SPring-8，使用互补金属氧化物半导体图像传感器和孔径掩模的组合，有四个不同的随机图案组成的孔与直径为27 μm和39 μm的分离。整个成像系统安装在一个25厘米长的紧凑型尺寸，并实现了<30角秒（半高全宽）的角分辨率。此外，我们通过Monte Carlo模拟表明，如果不同模式的数量增加到8或16，可以更有效地减少伪影。
The coded aperture imaging technique is a useful method of x-ray imaging in observational astrophysics. However, the presence of imaging noise or so-called artifacts in a decoded image is a drawback of this method. We propose a coded aperture imaging method using multiple different random patterns for significantly reducing the image artifacts. This aperture mask contains multiple different patterns each of which generates a different artifact distribution in its decoded image. By summing all decoded images of the different patterns, the artifact distributions are cancelled out, and we obtain a remarkably accurate image. We demonstrate this concept with imaging experiments of a monochromatic 16-keV hard x-ray beam at the synchrotron photon facility SPring-8, using the combination of a complementary metal-oxide-semiconductor image sensor and an aperture mask that has four different random patterns composed of holes with a diameter of 27 μm and a separation of 39 μm. The entire imaging system is installed in a 25-cm-long compact size and achieves an angular resolution of <30 arc sec (full-width at half-maximum). In addition, we show by Monte Carlo simulation that the artifacts can be reduced more effectively if the number of different patterns increases to 8 or 16.